In a normal call process, an audio signal acquired by a microphone of a communication terminal such as a mobile phone not only includes a call voice of a calling party (a called party) but also includes background noise in a current call environment. In order to improve call quality, noise reduction processing needs to be performed on the audio signal in the call process.
Currently, it is relatively popular that dual MICs (Microphone, microphone) are disposed on a body of a mobile phone to perform noise reduction processing, and a main working principle of the dual MICs is: A primary MIC is disposed at the top of the mobile phone and a secondary MIC is disposed at the bottom. During a call, the primary MIC is placed near a mouth of a calling party to acquire a call voice and background noise, and at the same time, the secondary MIC is placed far away from the mouth of the calling party and acquires only the background noise. The primary MIC and the secondary MIC transmit acquired audio signals to a noise reduction chip, so that the noise reduction chip performs, according to the background noise acquired by the secondary MIC, filtering processing on the audio signal acquired by the primary MIC, thereby achieving an objective of eliminating the background noise and retaining only the call voice.
However, when a calling party and/or a called party uses a headset for a call, because dual MICs are both disposed on a mobile phone and are both turned off during the call, only one MIC disposed on the headset cannot independently acquire background noise, and certainly noise reduction processing cannot be performed according to the background noise. In addition, a dual-MIC headset on which a primary MIC and a secondary MIC are disposed is commercially available. However, the headset performs, by using a noise reduction chip disposed in the headset and according to an audio signal acquired by the secondary MIC, noise reduction processing on an audio signal acquired by the primary MIC. Because a cost of the noise reduction chip is excessively high, a cost of the entire headset becomes relatively high, making popularization difficult.